Neither of my CB installs will run

ive been happy with CB for a few months, no issues at all.
I have my daily install, and CB specific install. im dual booting so same hardware, but different drives. No sharing between each install.

Since yesterday both installs are giving me issues. The both freeze up on startup, once the menu bar has appeared. Force quitting from Task manager causes Cubase.exe to appear in the list further down, but it cant be stopped. i get the error access denied.
On the odd occasion i can re launch CB, it complains it cant find the Yamaha ASIO driver and i have to use the generic one. most times i cant change to the Yamaha one, but when i do i can get play back, and midi input, but no sound out of anything im playing live. input meters are working, but no output.
I cant understand how both affected by the exact same issues.

CB11 Pro 11.0.41, Windows 10 64bit, up to date.

Have you done any very basic troubleshooting?

A far as i know.
I did get one install working, but when i went to re start it all the issue came back.
So far, i have started both in safe mode, with 3rd part add-ons disabled, and to use the basic preferences. this worked on the above one, once, but not again.
Ive noticed in Task manager that as soon as CB is launched, it shows as not responding. if it does manage to get to the point i can use the menus, it will only use the generic driver, not the Yamaha on. Wont even see it from the selection screen when booing in safe mode.
Ive not had one crash with one of the installs until today.

Ignore the midi issue above, i figured out what was going on with that.

forgot to add, it seems there is a process called Initialising Cubase that is no responding each time.
At the moment i have the audio select window frozen, i didnt even get the the menu this time

Hm… driver level stuff, perhaps?

Each install is using a totally separate boot of Windows, so nothing is shared.
I seem to have fixed it though. i have a feeling it might have been a project that messed with the Preferences.
When i was getting issues in the first install i booted in to the second, and loaded the same project. Then i was getting issues there. This is the only shared file between the two, and is just a simple midi track.
I got the cleaner install working somehow, then copied its preferences to the first install. so far both are holding up, even with this project open.

Still geeing this issue. 4 times in the past 10mins. first time its happened since my last post.
Once CB has not opened correctly i have to force quit it. it does close, but then a CB process appears in the task manager list that cant be shut down. This wasn’t there before i force quit. its not at the top where it shows whats running. only way i can get CB to run is to reboot my PC. unless i do that it wont pick up the Yamaha ASIO driver. it tries to load it but fails. every time.
Never used to have this happen, and ive not installed anything new.

The first step for pretty much all troubleshooting in Cubase is to start up n safe mode disable preferences and test to see if the problem still exists- is that something you’ve done?

Yep, i did all that a while ago. I even trashed my Preference files. This seemed to do the trick until today. I cant keep doing this though (and shouldn’t need to).
The biggest issue i have seems to be this CB process that is appearing in task manager after i stop the main CB process. And then it cant open the audio driver. Its like it gets locked to this process, but i cant quit the process if that makes sense.

Hm… kind of hard to help, not being in front of the machine. I wonder if @Martin.Jirsak has an idea about what is happening here?

This is a red flag to me, btw. It would seem to point to something at least being shared, or being the same?

Hi,

Wasn’t there any (silent) Windows update at the day, when the issue happened for the first time by any chance?

No, updates are all set to manual so i know when they are getting installed. The older install is my day to day OS, and that it up to date. The newer OS is still a few updates behind. I haven’t used it since my previous posts.
Other than hardware the only thing connecting to the installs would be the project’s themselves. I mostly use the older install, but if i have issue i switch to the newer one, and open the projects im working on. Recently these have just been very simple midi drum tracks.

Im happy to ignore the second install as far as the issues go, as if i can fix one i can fix both. As you can see from above, the gap between posts was quite long so its not like its happening every day.
I understand its hard to diagnose this, but i wanted to put it out there incase anyone had any ideas.